Selective removal of aflatoxin from azadirachtin containing compositions

Abstract

A method for the selective removal of contaminants, including aflatoxin, from azadirachtin-containing materials comprising contacting said materials with a binding agent capable of selectively binding contaminants compared to azadirachtin.

What we claim is: 
     
       1. A method for the selective removal of aflatoxin from an azadirachtin-containing composition contaminated therewith which comprises contacting said azadirachtin-containing composition with activated carbon, whereby said activated carbon selectively binds aflatoxin compared to azadirachtin. 
     
     
       2. A method according to claim 1 wherein the activated carbon is charcoal. 
     
     
       3. A method according to claim 1 wherein the activated carbon is added in an amount and for a time sufficient to remove substantially all of said aflatoxin from said azadirachtin-containing composition. 
     
     
       4. A method according to claim 1 wherein said contacting is accomplished by making a flowable mixture of said azadirachtin-containing composition in a solvent which is non-degrading to azadirachtin, and subjecting said mixture to activated carbon. 
     
     
       5. A method according to claim 4 wherein the solvent is selected from the group consisting of nitriles, substituted aromatics, chlorinated aliphatics, aromatic aldehydes, sulfones, ethers, esters, amides, sulfoxides, alcohols, alkyl carbonates, ketones, and mixtures thereof. 
     
     
       6. A method according to claim 4 wherein the solvent is selected from the group consisting of acetone, benzene, dichloromethane, ethanol, ethyl acetate, ethylene dichloride, methanol, methyl acetate, methyl t-butyl ether, methyl formate, 2-propanol, and mixtures thereof. 
     
     
       7. A method according to claim 1 wherein the azadirachtin-containing composition is a neem seed extract. 
     
     
       8. A method according to claim 1 wherein the selective removal of aflatoxin is carried out in a succession of treatments. 
     
     
       9. A method for the selective removal of aflatoxin from an azadirachtin-containing composition contaminated therewith which comprises the steps of: (a) mixing said azadirachtin-containing composition with an azadirachtin-soluble solvent and activated carbon for a time sufficient to bind aflatoxin, wherein said solvent is non-degrading to azadirachtin, and whereby aflatoxin is selectively bound to said activated carbon; and   (b) separating the activated carbon and bound aflatoxin from the azadirachtin-containing composition.   
     
     
       10. A method according to claim 9 wherein the activated carbon is charcoal. 
     
     
       11. A method according to claim 9 wherein the solvent is selected from the group consisting of nitriles, substituted aromatics, chlorinated aliphatics, aromatic aldehydes, sulfones, ethers, esters, amides, sulfoxides, alcohols, alkyl carbonates, ketones, and mixtures thereof. 
     
     
       12. A method according to claim 9 wherein the solvent is selected from the group consisting of acetone, benzene, dichloromethane, ethanol, ethyl acetate, ethylene dichloride, methanol, methyl acetate, methyl t-butyl ether, methyl formate, 2-propanol, and mixtures thereof. 
     
     
       13. A method according to claim 9 wherein the activated carbon is added in an amount and for a time sufficient to bind substantially all of said aflatoxin from said azadirachtin-containing composition. 
     
     
       14. A method according to claim 9 wherein the solvent is ethyl acetate. 
     
     
       15. A method for the selective removal of aflatoxin from an azadirachtin-containing composition contaminated therewith which comprises the steps of: (a) admixing said azadirachtin-containing composition with a solvent which is non-degrading to azadirachtin, wherein a flowable mixture is formed; and   (b) passing said mixture through a column of activated carbon wherein said activated carbon selectively binds aflatoxin compared to azadirachtin; and optionally   (c) repeating step (b) to remove substantially all of said aflatoxin.   
     
     
       16. A method according to claim 15 wherein the activated carbon is charcoal. 
     
     
       17. A method according to claim 15 wherein the solvent is selected from the group consisting of nitriles, substituted aromatics, chlorinated aliphatics, aromatic aldehydes, sulfones, ethers, esters, amides, sulfoxides, alcohols, alkyl carbonates, ketones, and mixtures thereof. 
     
     
       18. A method according to claim 15 wherein the solvent is selected from the group consisting of acetone, benzene, dichloromethane, ethanol, ethyl acetate, ethylene dichloride, methanol, methyl acetate, methyl t-butyl ether, methyl formate, 2-propanol, and mixtures thereof. 
     
     
       19. A method according to claim 15 wherein the azadirachtin-containing composition is a neem seed extract.